1. Field of the Invention
The present invention relates to a toner reservoir removably mounted in a developing device for visualizing an electrostatic latent image, which is formed on an image retainer, with a powdery developer by the electrophotographic or electrostatic recording method.
2. Description of the Prior Art
In an electrophotographic copying machine or electrostatic recording apparatus such as an image recording apparatus making use of an electrostatic image, generally speaking, an objective record is obtained by forming an electrostatic image on an electrostatic image retainer, by applying toner to the electrostatic image to visualize it by a developing device, and by transferring and fixing the toner image obtained to and on recording paper. After the image has been transferred from the electro-static image retainer its residual charges are erased by an electric elimination electrode and then its residual toner is removed by a cleaning device.
In the developing device described above, a toner in a toner supply unit supplied by a toner supply container is supplied in a necessary amount to a developer agitating unit. When the toner in its supply unit is reduced by repeating the supply from the toner supply unit, a toner supply indication lamp, for example, is lit, and the toner supply container is replaced to supply the toner.
On the other hand, the toner removed by the cleaning device is recovered by a toner recovery container disposed in the vicinity of the cleaning device.
In the prior art, the toner supply container and the toner recovery container are separately provided.
When the residual toner caught by the surface of the electrostatic image retainer is to be removed by the cleaning device so that the removed toner may be recovered in the recovery container, the timing of replacing the recovery container is of a major concern. This recovery container is usually not equipped with means for detecting and indicating the amount of recovery so that the recovery state has to be examined by removing said container.
About 70% of the toner supplied is consumed while the remaining 30% is removed by the cleaning device and recovered by the recovery container. If the replacement of the toner recovery container is neglected, the recovered toner will overflow the container to contaminate the surroundings. In order to prevent this, there has been disclosed Japanese Patent Laid-Open No. 58 - 173783 or Japanese Utility Model Publication No. 61 - 37008, for example, in which any special container is not prepared for the toner removed but the toner supply container is mounted on the cleaning device after the supply to accomplish the toner recovery.
As a united structure for the toner supply and recovery containers, on the other hand, there has been disclosed Japanese Patent Laid-Open No. 59 - 184373, for example, in which one toner container is equipped therein with a partition to form reservoirs for the toner before use and after recovery. With such positions of openings of the toner supply and the waste toner recovery, as disclosed in the embodiment, however, it is necessary to provide carry-in and carry-out means for releasing the toner from the toner container and for recovering it into the toner container. Another problem inclusive is the shielding performance between the partition and the container body. Thus, the united structure is short of reality.